Up to now, it has been known that a solid dispersion is formed by the dispersion of a drug hardly soluble in water in a polymer material to thus improve the solubility and easy absorbability of the drug. For instance, Griseofulvin is dispersed in a polyethylene glycol polymer as a water-soluble high molecular weight substance to give a solid dispersion for the improvement of, for instance, the solubility of the drug (see Non-Patent Document 1 specified bellow).
The compound represented by the chemical formula (A) as will be specified below or a pharmaceutically acceptable salt thereof, which is a subject of the present invention, is a compound or a salt, which shows an a 4-integrin-inhibitory action and which is useful as a therapeutic agent for treating diseases such as inflammatory, intestinal diseases and the compound or the salt can be produced according to the description disclosed in Patent Documents 1 and 2 specified below.
In addition, Patent Document 3 discloses a pharmaceutical preparation in the form of a solid dispersion which comprises, as effective components, wide variety of phenylalanine derivatives including the compound represented by the chemical formula (A), or pharmaceutically acceptable salts thereof and whose solubility and absorbability are improved. Moreover, Patent Document 4 discloses a sustained release type orally administrable pharmaceutical preparation.
In the pharmaceutical preparation containing the compound represented by the chemical formula (A) as an effective component, it would sometimes be necessary to increase the amount of the effective component to be incorporated into each individual dosage unit for satisfying a variety of requirements and for this reason, there has been desired for the development of a pharmaceutical preparation which is further improved in the solubility and the storage stability of the preparation in order to cope with such situations.